The Answer is D. Suspending a heavy weight with a strong chain.
Answer:
The correct answer is 574.59 grams.
Explanation:
Based on the given information, the number of moles of NH₃ will be,
= 2.50 L × 0.800 mol/L
= 2 mol
The given pH of a buffer is 8.53
pH + pOH = 14.00
pOH = 14.00 - pH
pOH = 14.00 - 8.53
pOH = 5.47
The Kb of ammonia given is 1.8 * 10^-5. Now pKb = -logKb,
= -log (1.8 ×10⁻⁵)
= 5.00 - log 1.8
= 5.00 - 0.26
= 4.74
Based on Henderson equation:
pOH = pKb + log ([salt]/[base])
pOH = pKb + [NH₄⁺]/[NH₃]
5.47 = 4.74 + log ([NH₄⁺]/[NH₃])
log([NH₄⁺]/[NH₃]) = 5.47-4.74 = 0.73
[NH₄⁺]/[NH₃] = 10^0.73= 5.37
[NH₄⁺ = 5.37 × 2 mol = 10.74 mol
Now the mass of dry ammonium chloride required is,
mass of NH₄Cl = 10.74 mol × 53.5 g/mol
= 574.59 grams.
Answer:
The correct answer is D
<u>18.016 g</u>
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Explanation:
Molecular Weight : It is the sum of atomic weights of each atoms present in the compound.
The molecular weught is measured in atomic mass.unit( amu) or simply"u"
This is calculated by using :
Molecular weight = number of atom x atomic mass of the atom
For H2O
Number of H atoms = 2
Number of O atom = 1
Molecular weight of H2O = 2(mass of H atom) + 1(mass of O atom)
Molecular weight = 2(1.00784) + 15.999
= 18.01558 u
= 18.016 u
Answer:
40.5 g/mL
Explanation:
Density is a measure of a substance's mass over its volume.
d = m/v
Therefore d = 255.15g/6.3mL = 40.5 g/mL
